Convenient synthesis method of methylprotodioscin

Abstract

A convenient synthesis method of methylprotodioscin belongs to the organic synthesis technical field. The method comprises the following steps: using the rich and cheap E / F full-ring-opening product of protodioscin, namely 26-choro-3beta,16beta-diacetoxy-22-one-5-cholestene as raw material to perform selective alcoholysis of C3-OAc and protection of C3-OH, then in THF / MeOH mixed solution, using the high selectivity of weak base K2CO3 to close E-ring to form C22-OH, then using methyl iodide to perform methylation to C22-OH, and finally performing a substitution reaction and deprotection of C3-OH. The synthesis of methylprotodioscin is realized in a concise and atom economy manner. The raw material and reagents used in the invention are cheap, the operation is simple, the reaction conditions are mild, the product is easy to separate and purify, the yield is high, especially by using the selective ring-opening reaction and the methylation reaction using the active methylating agent methyl iodide, the construction of furan ring in methylprotodioscin and the methylation of C22-OH can be effectively realized, and by attaching the same or different sugar chains to the C3 and C26 of the methylprotodioscin molecule, methylprotodioscin and multiple analogs can be synthesized. Therefore, the method provides a new synthetic approach for methylprotodioscin and other similar saponins.

Description

A Simple Synthesis Method of Methylprotodiosgenin technical field The invention belongs to the technical field of organic synthesis. Background technique Steroidal saponins are a class of oligoglycosides that combine sterol compounds with 27 carbon atoms as aglycones and oligosaccharides. They are widely distributed in nature, mainly concentrated in plants such as Liliaceae, Dioscoreaceae and Agaveaceae, and most concentrated in the genus Dioscorea and Liliaceae. From the structure, it can be divided into spirosterane type, furostane type and cholestane type. Furanostane type saponins are an important class of steroidal compounds, and most of them are disaccharide chain saponins in structure, usually in the aglycon Both C3 and C26 positions are connected with sugar chains, and its representative compound is methylprotodioscin (methylprotodioscin.fig.1), which was first isolated from fresh roots of Dioscoreaceae in 1974. Methylprotodioscin is usually Together with diosgen...

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Problems solved by technology

At present, the synthesis of methyl protodiosgenin has not been reported. How to synthesize methyl protodiosgenin concisely and efficiently using high-yield and cheap raw materials has attracted widespread attention from synthetic workers.

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